U.S. Pat. No. 4,651,421 discloses a cutterhead of the kind described above wherein the spool is axially fixed on an inner tubular piece and is provided with cams on one of its two flanges. These cams coact with stops of the switching member which is mounted in the housing in axially spaced relationship to the coil.
The filament coil on the spool must be wound in a direction corresponding to the rotational direction of the cutterhead if the cutting filament is to be paid out during rotation of the cutterhead when the ends of the filament effective for cutting are worn. The filament coil must therefore be initially wound for a predetermined direction of rotation of the cutterhead since its position within the housing is predetermined by the cams located on the flange of the spool. When the cutterhead is to be mounted on an apparatus having a drive connection which is configured for an opposite rotational direction of the cutterhead, then the filament spool must either be exchanged or the cutting filament must be unwound and then rewound in the opposite winding direction.